Had the same truck, but an '07 classic. Had it for over 200K miles and the worst problem I ever had was bad front hubs. Thats the kind of trouble-free ownership we all seek. Best overall truck I've ever had.
Previous RV was a 5000-ish pound TT. That truck handled it just fine on flat ground, but in the hills it struggled a little (even downshifting to 2nd gear). Never took it the mountains with this truck since we always had a diesel TV for that purpose.
You'll probably be OK in the 5000 pound range, but I wouldn't go past that.